Why Apple's $1 Billion Didi Deal Is A Sign Of Things To Come

In the 12 hours since Apple's announced investment in Uber's main Chinese rival, commentators have struggled to figure out why.

Could $1 billion for Didi Chuxing show that Apple's car-building efforts are further along than expected? Unlikely. Could the large investment be to integrate the computer maker's new services, like Apple Music, Apple Maps, and Apple Pay into China? Perhaps down the road. Or could the deal help Apple win approval from prickly government officials in China, a country CEO Tim Cook is visiting this month? Not so much--as a regulation-defying disruptor like Uber, Didi is hardly beloved by the Chinese government.

Apple's rivals have long used their profits to invest in startups, buying some outright and investing in others. Alphabet has two investment arms, Google Capital and GV, formerly Google Ventures. In recent years, Google has bought Nest and invested in unicorns like Uber and Magic Leap. Microsoft has done the same, with investments in Facebook before it went public, along with the purchase of Minecraft's parent company. And Facebook itself has been on a mobile growth spending spree under Mark Zuckerberg's reign, buying Instagram, WhatsApp, and Oculus.

Apple's investors have long wondered why Apple isn't putting its cash pile to better use. Other than the $3 billion Beats deal in 2014--which was as much for the streaming music technology as anything--Apple has largely stayed out of the investments game even as their profits piled up. In 2012, Apple started handing out dividends again, after 17 barren years. In 2013, the company started buying back shares, at a cost of $87 billion. Both are tried and true ways to return cash to shareholders.

Apple and Didi may eventually find some operational synergies to exploit, but hardware and ride-sharing are quite different businesses. The main goal for Apple has to be a sizable return on its $1 billion investment. One-tenth of the profit from a single quarter is hardly going to break the bank for Apple--but it carries significantly more upside buying a chunk of a high-growth startup than sticking it in almost anything else.

Apple still has more than $50 billion in cash and short term marketable securities, plus more than $177 billion in long term securities. That's a war chest that it could use to pursue growth opportunities other than simply building new products.

Does Apple want to fulfill every speculator's dream by buying Tesla (an expensive proposition to be sure)? Or could it turn its attention to various unicorns? If you can invest in Didi, why not Airbnb? Pinterest for a social network play? Dropbox to complement iCloud? DJI Technologies, another Chinese firm, has been called the Apple of consumer drones. Or maybe Apple doubles down on the anti-Uber ride-sharing alliance with India's Ola and Southeast Asia's Grab.

Moving into startup investing marks a major turning point for Apple. It also opens up all sorts of interesting possibilities.

Brian Solomon was a Forbes staff writer from 2011 to 2017 covering technology, entrepreneurs, billionaires, and more. Follow him on Twitter, Facebook and LinkedIn.